Round balers generally have a bale forming chamber defined by a pair of opposing side walls associated with an array of side-by-side belts, transverse slats trained on chains, a plurality of transverse rolls or a combination of these various elements, e.g., rolls and belts. During field operation, windrowed crop material such as hay is picked up from the ground and fed in a continuous stream into a fixed or variable diameter chamber. The hay is rolled into a cylindrical package within the chamber, wrapped with twine, net or the like and ejected onto the ground for subsequent handling.
U.S. Pat. No. 5,444,969, issued Aug. 29, 1995 in the name of Robert A. Wagstaff, et al, discloses a prior art round baler of the general nature described above. In this particular type of baler an expandable chamber is defined by a pair of fixed sidewalls, and a plurality of side-by-side belts cooperating with a series of transverse rolls, mounted between a pair of pivotally mounted arms. This arrangement of rolls and arms is commonly referred to as a sledge assembly. In the vicinity of the chamber where the belts and rolls operate in close proximity the transverse roll closest to the belts strips material from the adjacent belts that are trained about what is referred to as a follower roll. This is a common expedient in prior art balers having a chamber defined by rolls and belts.
The chamber includes an inlet opening in the front through which crop material is fed. Also included is a pair of take up arms pivotally mounted on the main frame, between which arms a pair of guide rolls are journalled. A biasing force on the take up arms urges the outer surfaces of the guide rolls against the belts to maintain tension and thereby prevent slack from occurring in the belts during expansion and contraction of the chamber. Density of the bale can be affected by varying the force on the take up arms.
The preferred embodiment of the present invention relates to an improved round baler in which a cylindrical package of crop material is formed in a chamber comprising fixed side walls and expandable transverse elements consisting of a combination of belts and rolls of the general nature described in the preceding paragraph. The '969 patent, cited above, is an example of many prior art patents, assigned to New Holland North America, Inc., that disclose this type of round baler. It is not uncommon in prior art round balers having this general configuration for the tubular idler rolls that support the belts to experience significant amounts of radial force that may cause the supporting walls to deflect slightly in the area of the walls adjacent the mounting assemblies. This type of deflection or buckling is commonly referred to as "oil canning", an example of which is illustrated at FIG. 5 of the drawings.
This oil canning problem, which has been encountered in various types of prior art stub shaft mounting assemblies, creates uneven transverse loading on the bearings, as illustrated by the force arrows in FIG. 5, resulting in premature bearing failure. To overcome this oil canning effect, tubular idler rolls have been mounted on solid shafts. The expedient of a solid shaft on which a tubular roll is mounted in well known in the prior art. Examples of this are shown in PCT Publication No. WO 97/16959, filed Oct. 15, 1997, and published May 15, 1997 in the name of John Dale Anderson, et al, and U.S. Pat. No. 5,205,105, issued Apr. 27, 1993 in the name of Bernard Krone, et al. In Anderson, et al, the arrangement is disclosed in a round baler idler shaft, while in Krone, et al, a floor roll for a round baler is depicted.
In the aforementioned prior art idler roll mounting systems employing a solid shaft, the Anderson, et al assembly includes a locking collar arrangement at one end of the shaft to secure it in a D-shaped holding disc, while in Krone, et al, the solid shaft 58 for a tubular floor roll is shown extending through both side walls, e.g., see FIG. 4 of Krone, et al.
The present invention is directed to an improved idler roll mounting assembly that overcomes the oil canning problem and is conducive to simple and inexpensive fabrication while also having the advantage of being readily serviceable. Although the invention is particularly adaptable to a round baler in which a cylindrical package of crop material is formed between expandable walls consisting of a combination of belts and rolls of the general nature described in the '969 patent, cited above, it is not limited to a specific round baler configuration. The '969 patent is merely cited as an example of the numerous prior art patents that disclose this type of round baler, referred to by some as a roll belt round baler, by virtue of the rolls and belts that define the bale forming chamber.
Unique structural characteristics of the present invention, described below, contribute to a round baler idler roll mounting system that provides for many implicit and explicit advantages over known prior art systems that will become apparent from the following description. Among other things, the invention enhances performance, simplifies construction and improves durability of round balers, regardless of the nature of the design, i.e., roll belt balers, roll balers, belt balers, etc. Additionally, there is a noted improvement in the serviceability of round balers incorporating the various embodiments of the mounting assembly of the present invention.